Remember your freeflowing regulator drill in OW cert? (Required in PADI, optional in SSI. Don't know about other agencies.)
Press on the purge button. Even without a diaphragm, the lever will open the valve. Hold it down, tilt your head to the side and half over the mouthpiece. Breathe slowly from the COLD rush of air from the mouthpiece. You have maybe 90 sec to reach the surface before your tank is empty. But you'll survive. And your breathing will be drier than you think!
Press on the purge button. Even without a diaphragm, the lever will open the valve. Hold it down, tilt your head to the side and half over the mouthpiece. Breathe slowly from the COLD rush of air from the mouthpiece. You have maybe 90 sec to reach the surface before your tank is empty. But you'll survive. And your breathing will be drier than you think!